This magnificent area, we don't really know what it's about. Where did it come from? Who built it? Why did they build it? Nobody knows. It looks like it could be Easter Island. It could be something else.

Sam.

So we go over here. So this whole area is built in the Paleolithic, the Neolithic area, 5,000 years ago. Imagine being here 5,000 years ago. How did they build it? How do they put it up? How is it possible? Maybe it was NASA. It could have been NASA that did it. So Stonehenge, what is it? Where does it come from? Did the Egyptians build it 5,000 years ago? I mean, how could this possibly have been done? Let's walk around it, let's get a tour of all different angles of it. Beautiful time of day.

Stonehenge, that silent city of stone on the Salisbury Plain in England. We see these magnificent structures and we're instantly struck by a question that has echoed through the millennia. How did this possibly come to be? But before we get to the how, let's just appreciate the what we're talking about. Stones that weigh as much as a fully grown humpback whale. The giant stones known as sarsen stones were quarried from about 20 miles away. They're the heavyweights, but the real head scratcher, the bluestones. These smaller five ton stones came all the way from the Presley Hills in Wales. That's a journey of over 140 miles.

Think about that. These ancient builders didn't have Amazon prime, they had grit ingenuity and we have to assume a lot of very sore backs. It's the ultimate prehistoric DIY project. And they didn't even have YouTube documentaries and tutorials like this one. So how did they do it? The truth is, no one knows for sure. It's one of history's greatest unsolved mysteries, right up there, along with the pyramids and the Easter island heads. But that doesn't stop us from making some very educated guesses with the help of modern science and a bit of logic. Forget alien interventions.

The real answer lies in human genius. The leading theory suggest a large combination of brute force and brilliant engineering. Were they rolling these giant behemoths on longs, hoisting them with massive A frames and rope? Maybe they built enormous earthen ramps. There are some huge dunes and berms nearby that some say are even more impressive than the stone structures themselves. Imagine trying to assemble the world's heaviest flat pack furniture from IKEA. But your instructions are 5,000 years old and written in, well, nothing at all. The builders even carved Woodworking joints, mortise and tenon into the stone. They were shaping the very bones of the earth with the precision of master carpenters.

Bob Vila take a back seat. It's a testament to the idea that with enough brain power, you can move mountains, or at least engineer parts of them. Now it's easy to get fixated on Stonehenge itself. But if you zoom out, you'll find it wasn't built in isolation. It was the spectacular centerpiece of a much larger sacred complex. The ancient motto seems to have been the same as your realtor today. Location, location, location. You have Avebury, a stone circle so vast it contains an entire village.